Intradermal injection device

ABSTRACT

Embodiments herein relate to the field of injections, for instance needle-free injections, and more specifically, to methods and apparatus for spring-driven intramuscular and intradermal injections. Provided in some embodiments are needle-free injectors adapted to deliver intradermal injections, as well as vial adaptors that are adapted to function as spacers when used with a needle-free injection device.

TECHNICAL FIELD

Embodiments herein relate to the field of injections, for instance needle-free injections, and more specifically, to methods and apparatus for spring-driven intramuscular and intradermal injections.

BACKGROUND

Needle-free injection systems provide an alternative to standard fluid delivery systems, which generally use a needle adapted to penetrate the outer surface of a target. Typically, needle-free injection systems are designed to eject the fluid from a fluid chamber with sufficient pressure to allow the fluid to penetrate the target to the desired degree. For example, common applications for needle-free injection systems include delivering intradermal, subcutaneous, and intramuscular injections into or through a recipient's skin. For each of these applications, the fluid must be ejected from the system with sufficient pressure to allow the fluid to penetrate the tough exterior dermal layers of the recipient's skin.

Intradermal injections, the least invasive of the three types, typically are employed when the injectate dose is very small or when visualization of the subject's local response to the injectate is desired. Subcutaneous injections typically are employed when prolonging the absorption time of the medication is desirable, when the dose is relatively small, or when the injectate is non-irritating. Intramuscular injections, the most invasive of the three types, typically are employed when rapid absorption is desired, when the medication is irritating, or when the dose is relatively large.

The efficacy of delivering a needle-free injection to a desired layer of the skin, subcutaneous tissues, or muscle may depend not only on the pressure with which fluid is ejected from the device, but also on the distance of the spray nozzle from the skin. For instance, whereas intramuscular injections typically require the nozzle to be placed directly against the skin to achieve the desired depth of penetration, intradermal injections typically require the use of a spacer between the nozzle and the skin surface. Additionally, the propulsion mechanism employed in many needle-free injector systems involves compressed gas. Such systems require the compressed gas to be replenished when depleted.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.

FIG. 1 is a side elevation, sectional view of an embodiment of an injector pen in a “fired” state, in accordance with various embodiments;

FIG. 2 is a side elevation, sectional view of an embodiment of an injector pen in an “arming” state, in accordance with various embodiments;

FIG. 3 is a side elevation, sectional view of an embodiment of an injector pen in an “armed” state, in accordance with various embodiments;

FIG. 4 is a side elevation, sectional view of an embodiment of a nozzle with an adapter for use with an injector pen, in accordance with various embodiments;

FIG. 5 is a side elevation, sectional view of an embodiment of the same nozzle with the adapter removed, in accordance with various embodiments;

FIGS. 6A and 6B are side elevation views of an embodiment of a nozzle adapted to fit into an aperture of an injector pen; and

FIGS. 7A and 7B are close-up side elevation, sectional views of a retaining mechanism adapted to retain a plunger in an armed position (7A) until it is released by a trigger mechanism (7B), in accordance with various embodiments.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents.

Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations are order-dependent.

The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments.

The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

For the purposes of the description, a phrase in the form “NB” or in the form “A and/or B” means (A), (B), or (A and B). For the purposes of the description, a phrase in the form “at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). For the purposes of the description, a phrase in the form “(A)B” means (B) or (AB) that is, A is an optional element.

The description may use the terms “embodiment” or “embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments, are synonymous.

In various embodiments, needle-free injector methods, apparatuses, and systems are provided. FIG. 1 illustrates an example of a needle-free injection device 100. Device 100 may include a body 12 to enclose various systems used to effect an injection. Body 12 typically is sized and shaped to be held comfortably in a user's hand and may take any suitable configuration. In some embodiments, body 12 may be formed from injection-molded plastic, although various other materials and fabrication methods also may be suitable.

As illustrated in FIG. 1, body 12 may be comprised of various subsections, such as housings 14, 16, and 18. Housings 14, 16, and 18 may be configured to couple to one another, for instance by threaded connectors 20, or by any other suitable connecting mechanisms, such as snap locks.

In various embodiments, body 12 may include an opening 22 in an end of the device 100 that may be adapted to receive a nozzle assembly 24. Body 12 also may include other apertures, such as one or more view ports, for instance to provide feedback or instructions to a user of the device. In some embodiments, the apertures may align with indicia, such as arrows or text, which instruct a user in proper operation of the device or convey information to a user, such as the current configuration or status of the device.

In various embodiments, nozzle assembly 24 may be configured to be selectively coupled to an injection mechanism. Turning to FIG. 2, nozzle assembly 24 may include an injectate chamber 26 adapted to accommodate a volume of injectate, and an outlet orifice 28 through which the injectate is ejected from device 100. In some embodiments, nozzle assembly 24 also may provide an interface with a recipient's skin. For instance, in some embodiments, nozzle assembly 24 may include a skin tensioning ring 30, which may help pull the skin taught during an injection procedure. Skin tensioning ring 30 may be particularly useful when device 100 is used to administer an intramuscular injection. Nozzle assembly 24 may further include a plunger 32 configured to move through injectate chamber 26 toward outlet orifice 28 to expel an injectate. Nozzle assembly 24 also may include a tapered Luer connector, for instance for coupling to a spacer device. Such spacer devices are discussed in greater detail below, and may be particularly useful when using device 100 to administer an intradermal injection. In various embodiments, nozzle assembly 24 may remain seated in the opening 22 of device 100 until released by sliding latch member 23 in a direction away from nozzle assembly 24.

FIGS. 6A and 6B, show an alternate embodiment of the device, in which nozzle assembly 24 may couple to the opening 22 via flanges 25 that may fit within notches in a flange retainer 27 adjacent opening 22. As shown, rotation of nozzle assembly 24 may couple and decouple nozzle assembly 24 from opening 22. In some embodiments, nozzle assembly 24 may lock into position when seated in flange retainer 27, and may be released by actuation of release button 29.

Device 100 includes one or more systems to effect an injection. For example, turning once again to FIG. 1, the illustrated embodiment shows an example of device 100 in a “fired” state (e.g., device 100 has not been armed or cocked in this illustration). In various embodiments, housed within body 12 is a drive source, such as a spring 34, disposed between spring stop members 36, 38, such that bringing spring stop members 36, 38 closer together compresses spring 34, and decompressing spring 34 pushes stop members 36, 38 away from one another. Spring stop member 38 is typically coupled to a rod 40 that may extend beyond spring stop member 36 to couple to lever 42 at attachment point 44. As illustrated in FIG. 2, which depicts device 100 in an “arming” state, device 100 may be armed or cocked by pivoting lever 42 at hinge 46. Pivoting lever 42 about hinge 46 results in tension on rod 40, which is transmitted to stop member 38, to move stop member 38 toward stop member 36, thereby compressing spring 34. Lever 42 is normally returned to its original position by tension on rod 40 provided by small spring like that depicted at 48. Small spring 48 is typically housed within a slotted link 50, which may be a component of stop member 38. In some embodiments, pivoting lever 42 about hinge 46, in addition to compressing spring 34, also may compress small spring 48 between slotted link 50 and spring stop member 52, which may be coupled to the end of rod 40. Small spring 48 typically applies sufficient force on lever 42 to return lever 42 to a home position, as shown in the FIG. 3 “armed” position.

In the depicted embodiment, stop member 38 is coupled to shaft member 54, which is in turn coupled to (or in contact with) plunger member 56, which is shown to be coupled to plunger 32. In some embodiments, shaft member 54 may make contact with plunger member 56, whereas in other embodiments, shaft member 54 may be physically coupled to plunger member 56, for instance with a threaded coupling or the like. Thus, pivoting lever 42 about hinge 46 results in the compression of spring 34 and the sliding of shaft member 54 (which is shown to be coupled to stop member 38) through a channel 58 in anchor member 60. In the depicted embodiment, this sliding of shaft member 54 moves plunger member 56 and plunger 32 away from outlet orifice 28. In other embodiments, such as when shaft member 54 is not coupled to plunger member 56, plunger 32 may be moved away from outlet orifice 28 prior to insertion in the device 100. For instance, this may be the case when pre-filled nozzle assemblies are used.

As shown in FIGS. 7A and 7B, once device 100 is cocked or armed, ball bearings 63 or other retention members may be forced out of their home positions by slide bushing 62 and into a notch 64 in shaft member 54, where they may retain shaft 54 in the cocked or armed position. In some embodiments, tension may be applied to both slide bushing 62 and front base 65 by spring 68, which also provides tension against latch members 66 and 23 and bearings 63.

Thus, to load device 100 with injectate, for instance in preparation for administering an injection, a user may simply place the outlet orifice 28 in contact with an injectate fluid, and pivot lever 42 about hinge 46 as shown in FIG. 2. In various embodiments, this action will create a vacuum in injectate chamber 26, and injectate will be drawn into injectate chamber 26 via outlet orifice 28. In various embodiments, device 100 will remain in the cocked or armed position until actuated by a user.

FIG. 3 illustrates an embodiment of the device 100 in a cocked or armed state, ready to be used to administer an injection. In use, outlet orifice 28 may be placed in contact with or adjacent to the skin of a subject in a desired location. In the depicted embodiment, pressure exerted on latch member 66 in the direction of the nozzle assembly and the patient receiving the injection will compress spring 68 against front base 65, releasing the ball bearings 63 from notch 64 and allowing spring 34 to propel shaft member 54, plunger member 56, and plunger 32 towards outlet orifice 28, returning them to their respective home positions as shown in FIG. 1. Plunger member 56 would expel injectate from injectate chamber 26 during this process, through output orifice 28, and into the body of the patient.

Thus, the disclosed injection devices 100 are configured to expel a volume of fluid, such as a drug. The word “drug” as used herein is intended to encompass, for example, and without limitation, any medication, pharmaceutical, therapeutic, vaccine, aesthetic, or other material which may be administered by injection.

In some embodiments, plunger 32 may be at least partially visible through the nozzle assembly 24 body. Plunger 32 may include first and second visibly distinct regions such that movement of the plunger 32 through the nozzle assembly 24 is measurable. For example, plunger 32 may include an over-molded tip in some embodiments, so that the tip is visibly distinct from the rest of the proximal portion of the plunger 32. In other configurations, the proximal portion may be visibly distinct from the distal portion of plunger 32. In some embodiments, injectate chamber 26 may include a dose scale to incrementally measure the volume of the injectate drawn into the chamber. In some versions of device 100, the dose scale may include indicia and the first and second visibly distinct regions of the plunger may be configured to align with the indicia. Additionally or alternatively, the dose scale may be a pre-molded dose scale having ribs to indicate each unit of measure. Additionally, one or more dosage spacers may be included in any of various points along the shaft member 54 and/or plunger member 56 in order to vary the volume of injectate drawn into the injectate chamber 26 when the device is loaded.

Some embodiments may include a system to prevent nozzle assembly 24 from being re-filled. U.S. Patent Application 2010/0076374 is incorporated herein by reference, and includes an auto-disabled plunger that includes a frangible section to provide additional protection so the cartridge cannot be re-used. Two other systems that may be used to prevent reuse of the nozzle assemblies are known as the B-2000 device and the Zetajet system. The B-2000 device has a proprietary nozzle attachment system consisting of three lugs on the nozzle that fit through three matching cutouts in the front cover of the B-2000 device. In embodiments, the nozzle may lock into place by inserting the nozzle into the device through the three cutouts, then rotating the nozzle approximately 60° where it bears on the front cover between the cutouts. There is a spring loaded detent within the device that provides feedback to the user when the nozzle is in its final locked position.

In various embodiments, the plunger for the B-2000 nozzle protrudes from the nozzle, but does not contact any portion of the B-2000 when the nozzle and plunger are inserted into the B-2000 device. In some embodiments, the B-2000 also may have an auto-disable features. When the B-2000 is fired, grippers within the B-2000 that are arranged radially around the plunger may grab the protruding portion of the plunger then force the plunger forward throughout the injection sequence.

The Zetajet device has a proprietary nozzle attachment system consisting of two lugs on the nozzle that fit through two matching cutouts in the front cover of the Zetajet device. The nozzle locks into place by inserting the nozzle into the device with the lugs oriented to fit through the two cutouts, then rotating the nozzle 90° where it bears on the front cover between the cutouts. In embodiments, there is a spring-loaded component within the device that both locks the nozzle into place and provides feedback to the user when the nozzle is in its final locked position.

In embodiments, the Zetajet nozzle may have a plunger tip that is set in place within the nozzle. In some examples, it is set into its final position when the nozzle is filled. The Zetajet device has a ram component in contact with the power spring that comes into close contact with the plunger tip when the nozzle is inserted. When the device is triggered, the ram is driven forward, pushing on the plunger tip driving the fluid out of the nozzle.

FIGS. 4 and 5 illustrate examples of a vial adapter 200 that may engage the nozzle assembly 24 (for instance, by coupling to the Luer connector 30) to couple the nozzle assembly 24 to a vial of injectate during loading of the nozzle assembly 24. The vial adapter may include a break-away spike component 102 that is typically adapted to penetrate the rubber seal on a drug vial during loading of the injector device 100. In addition, vial adapter 200 may include a flange 104 that is adapted to fit around the cap of a drug vial. In use, vial adapter 200 may be aligned with the vial cap, and downward pressure may be applied until spike component 102 penetrates through the vial seal, forming a sealed fluid conduit between device 100 and the vial.

In various embodiments, break-away spike component 102 may be coupled to vial adapter 200 by one or more flexible tabs 106 adapted to be disposed in apertures 108. Once seated, in the depicted embodiment flexible tabs 106 hold the spike component 102 in place with spring tension. As shown in FIG. 5, squeezing flexible tabs 106 permits decoupling of the spike component from the vial adaptor. Once the spike component 102 has been removed from the vial adapter 200, the adapter 200 may serve as a spacer device, for instance for use in administering intradermal injections. In some embodiments, the spacer device provides about ½ inch of clearance between the outlet orifice 28 and the skin. In particular, non-limiting examples, the outlet orifice 28 will typically be 0.055″ or 0.062″.

Although certain embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope. Those with skill in the art will readily appreciate that embodiments may be implemented in a very wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments be limited only by the claims and the equivalents thereof. 

What is claimed is:
 1. A needle-free injection device comprising: a body terminating in a nozzle; a fluid reservoir housed within the body, the fluid reservoir being adapted to receive a fluid injectate; a plunger disposed within the fluid reservoir; a shaft to which the plunger is mounted such that when the shaft is driven forward, the plunger is responsively driven forward; a spring-driven propulsion system having a first spring adapted to apply a bias force to the shaft and thus to the plunger to cause ejection of the fluid injectate through the nozzle; a lever adapted to arm the spring-driven propulsion system; and a rod extending between the lever and the shaft, the rod configured to transmit a load force between the lever and the shaft via a body of the rod so as to load the first spring, wherein the load force is opposite the bias force.
 2. The needle-free injection device of claim 1, wherein the first spring includes a first end and a second end, wherein the first spring is coupled to the lever at the first end and coupled to the shaft at the second end, and wherein expansion of the first spring imparts the bias force to the plunger which forcibly propels the plunger towards the nozzle.
 3. The needle-free injection device of claim 2, wherein a coupling between the shaft and a second end of the rod comprises a spring-loaded slotted member.
 4. The needle-free injection device of claim 3, wherein tension on the rod from the spring-loaded slotted member is adapted to bias the lever towards the home position.
 5. The needle-free injection device of claim 3, wherein the spring-loaded slotted member is adapted to control a degree of compression of the first spring.
 6. The needle-free injection device of claim 1, wherein the device further comprises one or more spacers disposed within the body and adapted to modify the capacity of the fluid reservoir.
 7. The needle-free injection device of claim 1, wherein the nozzle comprises a Luer taper that is adapted to receive a spacer component or vial adapter.
 8. The needle-free injection device of claim 1, further comprising a vial adapter that is adapted to be mounted to the nozzle, the vial adaptor comprising a spike connector adapted to provide a fluid path between a vial and the fluid reservoir.
 9. The needle-free injection device of claim 8, wherein the spike connector is removable.
 10. The needle-free injection device of claim 9, wherein the spike connector includes a biased structure that extends into the vial adaptor, and which by exerting a pressure against the biased structure permits removal of the spike connector from the vial adaptor.
 11. The needle-free injection device of claim 10, wherein the vial adapter is adapted to function as a spacer device when the spike connector is removed.
 12. The needle-free injection device of claim 1, wherein the rod is substantially axially aligned with the shaft during application of the bias force to the shaft.
 13. A needle-free injection device that may be fired to inject injectate into a patient, comprising: a body including a nozzle assembly; a fluid reservoir housed within the body, the fluid reservoir being adapted to receive a fluid injectate; a plunger disposed within the fluid reservoir; a shaft to which the plunger is mounted such that when the shaft is driven forward, the plunger is responsively driven forward, wherein the shaft includes a notch at a mid-section thereof; a ball-bearing retention system having ball bearings for retaining a position of the shaft when the ball bearings are held in position within the notch; a spring-loaded slide bushing for holding the ball bearings in position within the notch in the shaft until the device is fired; and a sliding latch member configured to releasably couple the nozzle assembly to the body, wherein a single spring provides bias for both the spring-loaded slide bushing and the sliding latch member.
 14. A needle-free injection device, comprising: a body terminating in a nozzle; a fluid reservoir housed within the body, the fluid reservoir being adapted to receive a fluid injectate; a plunger disposed within the fluid reservoir; a shaft to which the plunger is mounted such that when the shaft is driven forward, the plunger is responsively driven forward; a spring-driven propulsion system having a first spring adapted to apply to the shaft and thus to the plunger to cause ejection of the fluid injectate through the nozzle; a lever adapted to arm the spring-driven propulsion system; a rod extending between the lever and the shaft to transmit force between the lever and the shaft via a body of the rod to compress the first spring; and a second spring in operable communication with the lever, the second spring configured to bias the lever towards a home position.
 15. The needle-free injection device of claim 14, wherein the second spring is positioned to transmit force between the body of the rod and the shaft. 